Process of manufacturing camphene.



l FFICE.

OF DUSSELDORF, GERMANY, ASSIGNORS TO THE FIRM OF DR. SCHMITZ & 00., G.M. B. H.

PROCESS OF MANUFACTURING CAMPHENE.

No Drawing.

To all whom it may concern:

Be it known that we, JACOB SCHMITZ, doctor of philosophy, chemist, andGERHARD STALMANN, doctor of philosophy, chemist, subjects of the King ofPrussia, German Emperor, residing at 54 Himmelsgeisterstrasse,Dusseldorf, Kingdom of Prussia, German Empire, have invented certain newand useful Improvements in Processes of Manufacturing Camphene, of whichthe following is a specification.

As is known hydrochloric acid is split off with extreme difliculty frompinene hydrochlorid with the formation of camphene. While forexample theisomeric camphene hydrochlorid forms camphere with alcoholic solution ofpotash at the boiling temperature of alcohol after some hours, pinenehydrochlorid 'is not attacked at all by alcoholic solution of potash atthe boiling temperature of alcohol, but only such impurities as arepresent are transformed (German Patent 175,662). According to Riban and-Berthelot (Annales de Chimie et de Physique (5) 6, 357) it is necessaryto heat pinene hydrochlorid with alcoholic potash to say 200 C. forhours in order to split ofi? hydrochloric acid. The processes hithertoknown for manufacturingcamphene from pinene hydrochlorid, thereforeemploy (in so far as oxids or hydroxids are used) a medium dissolvingthe hydrochloridand the base. Thus, as already stated, Riban andBerthelot use alcohol, in German Patent 153,924 soap is used as thesolvent. The other processes utilize more costly means for splitting offthe hydrochloric acid, such as sodium acetate, benzoate and so forth,ammonia and aliphatic bases and with few exceptions (German Patent No.149,791) even then a solvent is employed.

We have found that pinene hydrochlorid reacts very readily with aqueoussolutions of weak alkalis in forming eamphene, when heated to say 160 C.in being stirred vigorously during the treatment. It has also been foundthat not only the'alkalis hitherto employed for splitting oflhydrochloric acid but also the earthy alkali hydroxids, in spite oftheir small solubility in water and slighter basieity, react veryreadily with pinene hydrochlorid in accordance with the methods referredto above. The capacity of these compounds for reacting is increased ifthe splitting oil of the hydrochloric acid is ef- Specification ofLetters Patent.

Application filed November 27, 1907. Serial No. 404,149.

Patented June 25, 1912.

fected in a concentrated aqueous salt solution (haloidsalts forexample). Alkaline earths may be replaced by other metallic oxids orhydroxids, either as such or in the form of their basic salts. such forexample as aluminium, magnesium. iron, lead. copper. The large capacityfor reacting possessed by these compounds was all the less to beanticipated, because in general the oxids and hydroxids utilized inaccordance with the present iny'ention present a smaller basicity thanthe caustic alkalis. so that it would have been expected that they wouldhave a smaller capacity for reacting. Contrary to expectations, however.the reaction in accordance with the present invention takes placeconsiderably more quickly than in the known processes. With theemployment of alcoholic solution of potash heating for 75 hours isnecessary; in the present process, on the other hand. a 4 to 5 hoursheating is sufficient in order to effect the splitting off of thehydrochloric acid quantitatively.

Quite apart from the inexpensivcness of the process, the followingconstitutes an important technicalefl'ect: lVhile in all the processesheretofore known, the chlorids.

forming, in the reaction. owing to their insolubility in the solventemployed must be eliminated in time or an excess of the bases employedneutralized (German Patents 154167, 153924), the metallic chlorid formedin accordance with the present process, as described above actsfavorably on the course of the reaction. It is therefore not necessaryto renew the reaction liquid at each single operation but after thereaction is completed the light stratum of camphene is removed from theheavy salt solution, and according to the concentration the latter ismixed with metallic oxids or hydroxids and then used for a freshoperation. The camphene obtained in this way is very pure and free fromhalogen compounds and resins.

Examples.

1. 20 kilos of pinene hydrochlorid are heated for about 8 hours to about200 C. with a solution of 6 kilos of hydrate of soda in 4 kilos of waterand thoroughly stirred. The camphene formed is isolated in the knownmanner for instance by distillation or extraction by means of a suitablesolvent.

2. 4 kilos of magnesium oxid are heated with kilos of pinene hydrobromidin the pinene hydrochlorid and 5 kilos of lime for about 5 hours whilebeing vigorously stirred, or heated for 3 hours to 200 C. in thedigester. The camphene formed may be removed and rectified and the saltsolution, after the addition of further lime may be employed for a freshoperation.

4. 20 kilos of pinene hydrochlorid are heated to 170 C. for 5 hours with8 kilos of ferric oxid and 10 kilos of water and the camphene formed isisolated as described in Example 1.

We claim- 1. The process for the manufacture of camphene which comprisesheating pinene hydrohaloid to temperatures above 160 centigrade withinorganic oxygen compounds of basic reaction leaving pinene haloidhydrate undissolved in the presence of water in the absence ofsubstances dissolving pinene hydrohaloid While stirring and thenseparating the formed camphene from the product.

2. The process for the manufacture of camphene which comprises heatingpinene hydrochlorid above 160 centigrade with lime and chlorid ofcalcium in the presence of water alone while stirring and thenseparating the formed camphene from the product.

In testimony whereof we afiix our signatures in presence of twowitnesses. JACOB SCHMITZ.

GERHARD STALMANN. Witnesses:

WILHELM FLAscHE, CLEMENS HEOKMANN.

